Electric switch



March 18 1924.

c. D. AlNswom-H ELECTRIC SWITCH 3 Sheets-Sheet l Filed Aug. 2. 1918 March 18 1924. 1,487,425

c. D. AlNswoRTl-l ELECTRIC SWITCH Filed Aug. 2, 1918 Sheets-Shoot 2 EQ gf @02T March 18 1924.

c. D. AlNswoRTH ELECTRIC swr'rcH Filed Aug. 2, 1918 3 Sheets-Shcot 5 Patented Mar. 18, 1924.

l* UNITED ASTATES PATENT OFFICE.

CHESTER D. AINSWORTH, 0F WOLLASTON, MASSCHUSETTS, ASSIGNOR T0 SEARS B.

CONDIT, JR., 0F BOSTON, MASSACHUSETTS.

ELECTRIC SWITCH.

Application led August 2, 1918. Serial No. 247,932.

To all 'whom it met concern Be it known tiat I, CHESTER D. Ainsthis purpose has its mechanism entirely en closed in a casing and its switch contacts are immersed in oil. rl`wo stationary sets of switchcontacts are provided, one set of which is adapted to connect the motor directly on to the line for starting, and after the motor has reached its normal speed, the operation of the switch is adapted to coni neet the motor to the other set of contacts `through an overload protective means such as a trip coil to the line. `mechanism of the switch is usually provided with means .whereby the operating handle must be held by the operator 1n the starting posit-ion, and upon the release thereof will return to neutral position, but which may be movedintorunning position and restrained in 'said position by the switch mechanism. The switch may be moved from running into neutral or open circuit position-'by the operation of the tripping means associated with the switch.

It is desirable that the operating mechanism of a switch of the type described be so constructed that the switch may be moved from running into neutra-l position by a corresponding movement of the handle independently of its movement thereto by the operation of the tripping mechanism.

The means I employ to attain this object` of my invention is in the provision in switch mechanism, of members forming in efl'ect, a toggle, which .by its relative disposition in the closed position of the switch, restrains the switch in said position against unintentionall movement therefrom but from which position it may be moved by the manual operation 'of the switch and byv electrically controlled tripping means.

The electrically controlled, or switch trip- The operating ping means, includes a spring, extended by a movement'of the switch into running position and normally locked in said extended position by the engagement of a link connected to the extended end thereof with .an abutment. l

The spring, after being extended and locked in extended position during closing move-ment of the switch, is adapted to be thereafter free from the switch mechanism to permit the switch to be moved by hand between running and neutral positions. Upon the suilicient energization of the tripping coils which control the lock of the spring, however, said spring is released from restraint and is caused to engage the switch mechanism to move the switch from running into neutral position.

The Overload responsive means or trip coils,associated with a switch of the type specified, are usually provided with a time limit means whereby the action of the trip coil to open the switch is delayed. The time limit means usually -comprises an oil iilled dash pot separatel attached to each trip coil, the plunger oi which is secured to the movable element of said coil.l Such dash pots or time limit devices are quite expensive to manufacture.

A second object of my invention is in the provision of 'time limit means associated with the trip coil of the switch, the component parts of which are formed of parts y of the trip coil itself, whereby an exceedingtime limit is provided.

The means by which this object of my invention is attained is in the utilization of the hollow tube upon which the trip coil or solenoid is wound for the cylinder of the dash pot and to provide the core or Inovable element of the coil with a cap which forms the piston of the time limitdevice. The piston also serves as a valve to govern the flow 0f oil into or from the cylinder whereby aV properly delayed action is obtained. The trip coils are arranged in the oil contained in the switch case whereby the necessity for a separate oilsupply for the time limit devices is obviated.

It is customaryto associate with a switch of the type'lr described a plurality of trip coils, each of which is in a separate phase of operate upon the same current flow, which is obviously desirable.

An object of my invention is, therefore, in the provision of means whereby a plurality of trip coils may be collectively calibrated or adjusted for a predetermined excess current iiow.

The means 1 employ to accomplish this object of my invention is in the provision of a member associated with the movable element of all the trip coils, and which is Y arranged to be raised or lowered to correspondingly raise or lower the movable elements in all of said coils, to thereby vary the adjustment of all the coils simultaneously. Means are also provided whereby the adjusting means can be locked in any said position.

1t is of importance that the movable switch members be rapidly moved fromstarting into running position, whereby the speed of the motor will not drop appreciably during the movement of the switch members between the running and starting contacts and thereby cause a second excessive current iow through the motor, and it is also of importance that means be provided whereby the order of operations of the switch may be predetermined, whereby the operator can initially move the switch only into the starting position, from which position he is constrained to move it rapidly toward running position to arrive at said position.

The means I employ to accomplish these features of my invention is the provision of ay latch pivoted to the switch casing and arranged for normal sliding engagement with a component part of the switch handle.

Said latch is provided with a notch upon its working face, which is arranged to engage the switch handle in its neutral position, and from which position said handle can move only in a direction toward the starting position of the switch. 1f a movement of the switch handle from the starting position toward running position is sufliciently rapid, the notch in the latch by the arrangement of said latch is ineective in engaging the switch handle, and thereby permits the movement of the switch members into running position, in which position they are restrained by the switch mechanism against unintentional removal therefrom.

A yet further object of my invention is the structure of the switch and the switch housing, which are constructed mainly from sheet metal stampings, whereby a cheap and yet durable switch is atta-ined.,l

Certain features of the invention herein shown are set forth in my co-pending application, Serial #210,392, led January 4, 1918, and my Patents #1,290,863, dated J anuary 14, 1919. and #1,321,582, dated November 11, 1919.

Fig. 1 is a side elevation of the switch.

Fig. 2 is a sectional view along lines 2f-2 of Fig. 3.

Fig. 3 is a plan view of the switch withthe removable part of the cover removed.

Fig. 4 is a sectional View of the switch along lines 4-4 of Fig. 3.

Fig. 5 is a detail of the switch operating and locking mechanism in the starting position of the switch with the tripping mechanism set.

Fig. 6 is a detail of the switch operating and locking mechanism in the neutral or open position of the switch with the tripping mechanism set.

As `shown here, the switch structure is mounted on and supported by the insulating base 10 arranged within the switch casing or housing 11. Said housing has ears 12 integrally formed therewith and refleXed to form supports for the base 10, which is secured to said ears by means of bolts 13. The casing 11 is provided with a covercomposed of two portions 14 and 15. The cover portion 14 is formed with downwardly refleXed edge portions which are arranged to engage the side walls of the casing 11. Said cover portion 14 extends partially over the casing 11, and its forward edge is flared or raised to form a seat or socket 16 for the I end portion of the cover' 15, which is arranged to slide over the casing 11 into closing position with its edge rearward disposed beneath said raised portion 16.

The cover portion 14 is secured to the casing by suitable screws 17. The cover portion 15 is provided with downwardly reflexed edge portions arranged to engage the side walls of the casng 11 to more effectively close the junction between the cover and side wall, and is provided, at a part thereof adjacent the front wall of the casing, with a depending lug or ear 18, which constitutes one part of the means whereby the cover may be locked to the casing against unintentional. removal therefrom. Said depending lug 18 is formed 'with two diametrically opposed quadrantal sectors 19, and the front Wall of the casing 11 is formed with correspondingly formed sectors, which are in substantial alignment when the cover is in position. f

The corresponding straight walls forming the bounds of the sectoral slots are parallel, and the opposite walls are spaced apart a suiicient distance to enable the locking lever 20 to be disposed therein. Said lever 2O consists of a flat strip disposed through the front wall of the casing and the dependent lug 18 of the cover, and downwardly bent within and without the enclosure to prevent removal therefrom and to form an exterior and handle portion 21.

The dependent lug 18 is formed with a slot 22 extended from the end thereof to the sectoral slots to permit the' entrance of the locking lever 20 therein. In the positioning of the cover upon the case, the locking lever is turned upward to the right, Fig. 1, whereby it may enter the slot 22 in the lug 18 and the cover thereby permitted to move to closed position. With the `cover in closed position, the locking handle 20 ismoved' to the vertical position, whereby its engagement with the parallel walls of the slotted sectors prevents the unintentional removal of the cover from the casing.

The casing 11 is provided with suitable arms 23 formed of stamped material, whereby the switch may be secured to a support. An oil receptacle or container 24 is secured to the lower part of the casing 11 by the locking means similar to the meansJ used in locking the cover above described, and the switch contacts depending from the insulatin base 10 are immersed in the oil contained in said receptacle.

the resilient strips 32 secured to the insulating base by bolts 33, and to which connection is adapted to be made with the line. Said resilient strips terminate 'in the detachable contact members 34, secured thereto by screws 35. Said strips are secured intermediate their length betweeny two insulating bars 36 by means of boltsv37, whereby said strips are united for simultaneous movement. A metal strip 38 is secured to said bars 36, and is formed with a reilexed portion 39 which is engaged by thehooked endf the switch operating rod 40.

The switch operating mechanism, arranged inthe enclosure 11 above said inw sulating base 10, includes the switch operat-v ing shaft 41, which is formed with a crank portion 42 intermediate its length. An end punched out ears 64 which are disposed in ing 43 in the rear wall of the casing 11,"l

and the other end of said rod or shaft 41 is arranged in a slot 44, by means of which the operating shaft with its assembled associated members may be simply and easily assembled within the switch casing.

The switch operating rod 40 'projects through an opening 45 in the insulating base 10, and is journalled to the crank portion 42 of the operating shaft 41, and thereby forms a connecting rod whereby the movement of the operating shaft is transmitted to the movable switch members.

The tripping mechanism, by means of which the switch may be caused to move from closed to open position, includes the reflexed member comprising segments or arms 46 and an end connecting wall 47. Said member is loosely arranged on the switch operating shaft 41. The end wall of said reflexed member is adapted to engage a dog or lug 48 affixed to Vthe operating shaft in a movement of said shaft from starting to running position to set the tripping mechanism. A link 49, which forms the latch, is pivoted at 50 to said reflexed member, and is formed with a recess or notch 51 therein. Said notch is adapted, in the locked position of the switch, to engage aroller 52 arranged on a pin 53 between the Wall of the casing 11, and a frame member 54 secured to said wall, and in which wall and frame said pin 53 is secured.

A retractile spring 55 connects the pin 53 and the pin 50 in the reflexed member on the operating shaft, and upon the disengagement of said latch with the roller, serves to move said reflexed member, and because of the engagement of the end wall 47 thereof with the lug 48 secured to the switch operating shaft 41, to correspondingly move said shaft and associated switch mechanism into neutral position.

rI fhat portion of the latch 49 extended beyoud the notch 51 has formed therein a flange ortion 56, which is adaptedv to be engagedJ by the striking rod of the tri ping mechanism hereinafter to be describe The overload tripping coils 57. are secured toa frame which forms part of the magnetic lcircuit for said coils, and which comprises with two depending lugs 62, which form.

pivotal supports for the tripping frame 63. aid tripping frame 63, is formed with holes 65 of the depending lugs 62, and which form pivots about which said trame is angularly movable to cause the tripping of the switch.

Said tripping frame is formed with inturned end portions 66, which are disposed in the path of movement of striking disks 67 secured to the plungers or movable elements 68 ot the tripping coils, and which are adapted to be engaged by said striking disks upon suiiicient energization of said coils to move said tripping frame upward to cause the opening ot the switch.

' A rod 69 formed with a reduced and hooked end portion 70, which is pivotally disposed within and projects through an opening 71 in an arm ot' the tripping frame 63, extends through an opening 72 in the top portion 58 ot' the trip coil supporting frame, and is disposed under the flange portion 56 of the latch 49. ln a movement of y 55 to move the switch mechanism from running position to open position.

T he side wall 59 of the trip coil supporting frame is formed with reflexed portions or ears 73 arranged to form supports for the terrminal wires of the trip coils 57 which project through insulating tubes 74 to make contactY with the stationary switch terminals 25 and 26, and which are secured to said ears 73 by means of the clip 75.

The movable elements of the overload trip coils are provided with pistons 76, closely but slidably iitting the tubes 77 forming the central core of the solenoids. Said pistons 76 form the time limit means for said coils, and are provided with valved means, not shown,-restricting the escape of oil from within said cylinders or tubes 77 upon an upward movement of the plungers 68, and thereby retarding such upward movement, but permitting the unrestricted downward movement of said plungers in their return to normal osition.

The stri ing disks 67 also form auxiliary time limit means, but are not depended upon to entirely govern the operation of the trip coils.

Means are provided whereby the movable elements of said trip coils may be collectively adjusted to condition said coils for operation upon a predetermined current flow therein. Said meanscomprise a metal strip 78 slidably arranged inthe top portion 58 and lower portion 59 of the'trip coil supporting frame, and disposed between said trip coils. A win nut 79 is secured to the top portion of said strip and projects through a slot 8O in the vertical upright 81 secured to the top portion 58 of said frame. Said upright 81 may be suitably calibrated to indicate the current value for which the trip coils are adjusted and the wing nut 56 forms means whereby the strip 78 may be secured to said upright 81 against unintentional movement thereby securing an adjustment of the trip coils at any particular current value.

The strip 78 is provided with a lower reflexed horizontal end portion 82`disposed between and below the striking disks 67 of the movable elements of the trip coil. A fiat strip 83 is riveted, or otherwise secured, to said portion 82, and extends beneath the movable elements of said coils, which are arranged to normally rest thereon. movement of the calibrated strip 78 in a vertical direction will thereby simultaneously move in the same direction the movable elements 68 of said trip coils, and thereby simultaneously alter the calibration or adjustment of said coils.

An operating handle 84 is secured-to that portion of the switch operating shaft 41 extending beyond the front frame of the casing 11. The operating shaft 41 projects bevond the hub of said handle, and has a bearing at 85 in the wall of a cover 86 disposed on the front wall of the casing 11. Said cover is formed with two inturned ears or lugs 87, which are disposed in the path of movement of the operating handle beyond full starting or running position.

The means whereby the order of operating of the switch `is predetermined, and the means whereby the operator is constrained to move the switch handle rapidly from starting to running position to succeed in removing the switch into running position comprises the arcuate latch 88 pivoted at 89 to said cover 86. A pin 90 is secured to the handle 84, and is arranged to slidably engage the lower :tace 91 of said latch. Said latch 88 is formed with a notch 92 in the lower face 91 thereof, which is normally adapted to engage the pin in the o en or neutral position of the switch. he notch is so arranged as to prevent a movement of the switch handle, and consequently of the switch mechanism', from neutral to running position, but does not restrict the movement of the switch handle from neutral to starting position.

The movement of the switch from running to starting position raises the latch. If the movement of the switch handle from starting position to running position is suciently rapid, the rate of descent of the pin 90 secured to the handle is greater than the free fall by gravity of the latch 88, and therefore, the pin 90`wil1 pass b the slot 92 in the latch before said latch suciently tu enable it to efeively engage as 'fallen thepin, and thereby the switch may be moved into running position.

I claim:

1. In an electric switch, switch mechanism arranged for normal restraint vin closed position including anoperating shaft, a lug secured to said shaft, a member loosely arranged on said shaft, having a component part thereof arranged for engagement with said lug upon a movement of said member in one direction, a spring connected with said member normally tending to move said member in a direction to cause the opening of the switch. a latch pivoted to said member arranged to normally restrain said spring against operation to trip the switch, and electrically controlled means for releasing said latch.

2. In an elec-tric switch, switch mechanism arranged for normal restraint in closed position including an operating shaft, a lug secured to said slaft, a member loosely arranged on said shaft and adjacentvsaid lug, said lug and member being arranged for independentrrelative movement in one direction and for conjoint movement in another direction, a spring normally tending to move said member into engagement with said lug to cause a movement of the switch from closed position, a roller' pivoted to the switch housing, a link pivoted to said member and arranged for engagement withsaid roller to normally restrain said spring against operation to open the switch and electrically controlled means to govern the K operation of said link.

3. In an electric switch, a plurality of trip coils, a supporting frame therefor, and a tripping frame pivoted to said supporting frame having portions thereof arranged to be engaged by t-he movable elements of said trip coils upon a predetermined current flow to cause a movement of the switch from closed position.

4. In an electric switch, a plurality of tripcoils, a supporting frame therefor, a tripping frame having portions thereof arranged to be engaged by t-he movable ele` ments of said trip coils to cause a movement of the switch from closed position, tripping ,A mechanism controlling the opening of the switch, and a -rod lpivoted to said tripping frame extending through said supporting frame for engagement with the tripping mechanism upon an upward movement of said tripping frame.

5. In an electric switch, a. plurality of trip coils, a supporting frame therefor, lugs depending upon said frame, a tripping frame having stamped out ears pivotally arranged in said depending lugs, said tripping fra-me having end portions arranged to be engaged bythe movable elements of said coils upon a predetermined current flow to cause the opening'of thev switch,

tripping mechanism controlling the opening of the switch, and a rod having a reduced, hooked end portion pivoted to said tripping frame and arranged beneath a latch of the tripping mechanism to cause the 0peration thereof to open the switch upon a movement of the tripping frame.

6. In an electric switch, an enclosing casing, switch mechanism disposed therein, an operating shaft extending through said casing, said shaft having a bearing in the rear wall of said casing, a slot in the front Wall of said casing in which said A.shaft is disposed, and additional shaft supporting means` beyond said front wall.

7. In an electric switch, an enclosing casing, switch mechanism disposed therein,

an operating sha-ft extending through said y casing, said shaft having a bearing in the rear wall of said casing, a slot in the front wall of said casing in which said shaft is disposed, an operating handle arranged on the end of said shaft beyond said front wall and a cover partially enclosing saidv handle and forming a support for said shaft beyond said front wall.

8. In an electric switch, a-n enclosing casing, switch mechanism disposed therein, an operating shaft extending through said casing, an operating handle secured thereto, a cover partially enclosing said handle and forming a bearing su port for said shaft, and integrally forme lugs on said cover arranged to 4limit the movement of said handle.

9. In an electric switch, the `combination of stationary and movable vswitch members, operating mechanism including means normally tending to open the switch and means to lock the switch in closed position, and switch-tripping means comprising a. spring adapted to be stressed into switchtripping condition by a movement of the switch to closed position, means to lock the tripping means in such condition, said op-` erating and tripping mechanism arranged to admit of manual movement of the switch from closed position independent of the tripping mechanism, and electrically controlled means to release the lock on the spring to admit of its forcible release of the lock on the switch to cause the switch to open. 1

10. In an electric tion of stationary and movable switch members, operating mechanism including means normally tending to open the switch and ,means to lock the switch in closed position,

and switch-tripping mechanism arranged to be engaged by said operating mechanism to be set. during a switch-closing movement and to ypermit'the switch to be independently manually moved: to open' posltion, said tripping mechanism comprising an actuating member, means to lock it m setfconswitch, the combina,-

dition, and electricallycontrolled means to release the: lock to cause the tripping mechanism to forcibly release the switch locking means whereby to cause the switch to open.

l1. In an electric switch, switch mechanism arranged for normal restraint .in closed position, tripping means therefor including a member mounted on a movable component of the switch mechanism for independent movement in one direction and for conjoint movement therewith in another direction, a s ring connected with said member normal y tending to move said member in a switch-opening direction, and a latch carried by said member arranged to govern the action of said spring. In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

CHESTER D. AINSWORTH. W'itnesses: v

T. T. GREENWOOD, H. B. DAVIS. 

